All I have to do is bet on the winner, and I'll never lose.

Biff Tannen (Thomas F. Wilson)

4 seconds sound clip from the Back to the Future Part II movie soundboard.

You can hear this line at 00:58:10.229 in the Blu-ray version of the movie.

Quote context

[...]

- How do you know about that?

- My father told me about it.

- Your father?

- Before he died.

- Yeah. Right.

- So there I was, minding my own business.

- This crazy old codger with a cane shows up. He says he's my distant relative. I don't see any resemblance.

- So he says, 'How would you like to be rich?' So I said, 'Sure.' So he lays this book on me.

- He says this book will tell me the outcome of every sporting event till the end of the century.

- All I have to do is bet on the winner, and I'll never lose.

- So I said, 'What's the catch?' He says, 'No catch. Just keep it a secret.'

- After that, he disappeared. I never saw him again.

- Oh, and he told me one more thing.

- He said, 'Someday a crazy, wild-eyed scientist, or a kid may show up asking about that book. And if that ever happens...'

[...]